Boiler viewing assembly



y 8, 1968 B. R. KING 3,385,285

BOILER VIEWING ASSEMBLY Filed Nov. 21, 1966 5 1 h 5 INVENTOR.

/ g ,2; BILLY 1?. KING 7 l r\ 4; 25 fl w g United States Patent 0 3,385,285 BQ llLER VIEWING ASSEMBLY Billy R. King, Bakersfield, Calif., assignor to Atlantic Richfield Company, Philadelphia, Pa., a corporation of Pennsylvania lFiled Nov. 21, 1966, Ser. No. 595,787 12 tllaims. (Cl. 126-260) ABSTRACT OF THE DISCLOSURE A viewing door for a boiler which includes a support plate rigidly mounted on the distal end of a hollow cylindrical spacer and having a port aperture in registration with the interior of the spacer communicating with the interior of the boiler, a rigid slide plate having a blank portion at one end and a lens mounted in an aperture in the other end resiliently slidably mounted on the port plate for reciprocal motion for permitting the lens to be selectively placed in registration with the port or removed in spaced relation therefrom for cleaning and including stops at each end of the slide plate, one of the stops com prising a removable actuator member is disclosed.

This invention is directed to an apparatus for viewing the interior of a furnace or boiler, and more specifically, is directed to a sliding viewing door for an oil fired steam injection boiler.

Visual inspection of flame patterns in furnaces and oil fired steam injection boiler interiors is often desirable and many viewing doors have been developed for this purpose. Since combustion within furnaces and oil fired steam injection boilers, however, is only partially complete, severe sooting of the viewing lenses obstructs vision and often renders them useless. Cleaning the lenses has required either complete removal of the viewing assembly or removal of the lenses from the assembly. Such removal vents to atmospheric pressure the boiler observation ports as they are either totally open or the pressure seals are broken. Complete shutdown of the boiler may be required to replace the lenses since flames and gases often shoot out from the open observation ports by several feet. This is dangerous to personnel working near the boilers and an inefiicient operation of the boilers. While the problem of visual inspection of internal flame patterns is particularly important in oil fired steam injection boilers, it is common to all high capacity heating vessels such as oil and coal furnaces and the like.

Previous attempts to overcome the problem of sooting by construction of viewing assemblies with movable parts have been plagued with problems caused by severe temperature variations which the assemblies must withstand. Differential expansion and contraction of the movable parts has caused binding and warping of these assemblies rendering them almost totally ineffective. For example, the flame temperature in oil fired steam injection boilers is about 2000 F. and the temperature at the observation port entrance may be 700 to 800 F. whereas the insulated boiler plates and remote portions of the assembly are usually approximately the outdoor temperatures of the boiler site.

Accordingly, it is an object of this invention to provide a novel assembly for visual inspection of the interior of boilers, furnaces and the like.

Another object of this invention is to provide an assembly for viewing the interior of a boiler wherein the assembly viewing lens is easily cleanable in situ.

Still another object of this invention is to provide an assembly for viewing a boiler interior wherein the viewing lens is adjustably spaced from the furnace side wall.

3,385,285 Patented May 28, 1968 Another object is to provide a boiler sliding viewing door assembly having a slidably mounted lens which is only subjected to sooting during brief periods when the boiler flame pattern is being viewed.

Yet another object of this invention is to provide an assembly for viewing the interior of heating vessels, wherein said assembly has a plurality of moving parts including means for compensating for unequal thermal expansion of the parts.

Another object is to provide a sliding viewing door for boilers which can he slid into and out of viewing position even though severe soot buildup has occurred.

Still another object of this invention is to provide an economical assembly for viewing the interior of a boiler wherein the assembly viewing lens can be easily cleaned without removal from the assembly or the boiler and without opening the side wall observation ports to atmospheric pressure.

Another object of this invention is to provide a sliding glass viewing door which is spacedly mounted on a boiler side wall and which can be readily cleaned in situ.

Yet another object of this invention is to provide a sliding glass viewing door which is spacedly mounted from the boiler side wall in registration with an observation port wherein a constant pressure is evenly applied to the viewing door and wherein the viewing door is slidably movable out of registration with the observation port.

Another object of this invention is to provide a sliding viewing door for observing a boiler interior wherein a substantially constant pressure is applied on the viewing door at all times.

Another object of this invention is to provide a sliding viewing door having a handle and stop member for limiting door movement and which can be partially withdrawn from the assembly for easy removal of the assembly slide plate.

These and other objects of this invention will become more readily apparent from the following detailed discussion and the appended claims when taken in conjunction with the drawings, wherein:

FIG. 1 is a partially sectioned end view of one em bodiment of the sliding viewing door assembly of this invention mounted on a furnace side wall observation port;

FIG. 2 is a side view of the sliding viewing door assembly of this invention in spaced relation from a partial cross section of a furnace side wall and observation port;

FIG. 3 is a perspective view of the sliding viewing door assembly of this invention; and

FIG. 4 is a sectional View of the slide plate taken through the viewing lens substantially along line 4-4 of FIG. 3.

Briefly, this invention is directed to a sliding door viewing assembly wherein the viewing lens is mounted on a slide plate for sliding into and out of registration with a boiler observation port and the mounting assembly is so constructed that the port is always sealed, the lens can be cleaned in situ without danger of burn injury when out of the viewing position, and the slide plate can be moved easily into and out of viewing position in spite of differential expansion and contraction of the assembly parts.

Referring now to the drawings in more detail, FIG. 1 shows a boiler portion comprising a side wall plate ill), a refractory lining l2 and an internally flared observation port 14. An internally threaded annular sleeve in is attached to side wall plate 1% to extend longitudinally of observation port 14 from the side plate. Sleeve 16 may be welded or otherwise fixedly mounted on side plate it? and is internally threaded for receiving the sliding observation door assembly of this invention. conventionally, oil fired steam injection boilers are provided with three observation ports, such as port 14, for viewing the flame patterns of the boiler interior. Any number of such ports may be used, however.

The door assembly of this invention as shown in FIG. 1 is provided with a hollow cylindrical mating spacer member 18 which carries external threads 20 at its lower end portion for fitting into sleeve 16. A standard 2 inch threaded pipe has been found to be suitable for the spacer member. Spacer member 18 is rigidly mounted, preferably by welding, to a substantially planar slide support base 24.

Support base 24, as best shown in FIGS. 2 and 3, is provided with an annular through bore 26 of substantially the same diameter as the internal diameter of spacer member 18. The slide support base is rigidly mounted to cylindrical spacer 18 so that through bore 26 is fixed in registration with the internal bore of member 18. Support 24 is also provided with four threaded apertures 27 for receiving spring-loaded clamping screws 32 which resiliently mount a pair of side guide track rails 34 in position as shown in FIGS. 1 and 3. Rails 34 are each provided with a longitudinally extending upper pressing flange 35 for a reason to be discussed.

Clamping screws 32 comprise a flat head 36, a shank 38 and a threaded lower end portion 40. A coil spring 42 is mounted about shank 38 to apply resilient pressure between clamping screw heads 36 and track members 34. By adjustment of screws 32, substantially constant downward pressure can be maintained by track members 34 along the length of support base 24.

As best shown in FIGS. 3 and 4, a rectangular slide plate 44 having lower guide track following side flanges 45 for mounting subjacent flanges 35 on track members 34 is slidably positioned on the assembly base 24. Springs 42 maintain pressing flanges 35 snugly in contact with follower flanges 45 at all times. Even though temperature variations cause expansion and contraction of plate 44 and rails 34 by different degrees due to the difference in distance from the boiler flame, springs 42 always permit relatively free and easy sliding of plate 44. The pressure of springs 42 is easily regulated by adjustment of screws 32 and is preferably maintained slightly higher than the maximum boiler pressure. This prevents loss of pressure through port 14 and, since the normal boiler pressure is about 4 inches of water, still permits plate 44 to be slid easily into blanking or viewing position.

Slide plate 44 is also provided at one end with an annular through bore 46 of substantially the same diameter as bore 26 in support base 24. As shown in FIG. 4, bore 46 is provided along its upper edge with an annular inset 48 for receiving a circular transparent viewing lens 50. Viewing lens 50 is held in place by an annular clamping ring 52 with metal set screws 54 as best shown in FIGS. 3 and 4. The viewing lens is preferably constructed from high temperature, tinted borosilicate glass, such as Pyrex, but any transparent, thermally resistant material can be used.

The opposite end of plate 44 forms a sealing blank portion 55 which is in sealing relation with bore 26 when viewing lens 50 is slid out of its viewing position. Pressing flanges 35 and following flanges 45 firmly maintain blank portion 55 in contact along its length with support base 24.

Slide member 44 is also provided with an internally threaded smaller diameter through passage 58 (see FIG. 4) adjacent one end for receiving a cylindrical combination handle and stop bolt 60. Bolt 60 is provided with a threaded portion 62 adjacent one end for mounting it in threaded passage 58 of slide member 44. Bolt 60 may also be provided with a knob 64 at its one end for a handle grip and a tapered reduced diameter abutment portion 66 at its opposite end for a slide limiting stop. An abutment stop plate 70 is also mounted at the pposite end of slide member 44 by means of metal set screws 72 as best shown in FIG. 3.

Bolt 60 serves the dual purpose of a slide actuator and a limit stop to prevent inadvertent advancement of slide member 44 off of base 24. It is usually necessary, however, to periodically remove slide plate 44 from the support base to allow the flame to blow out carbon buildup on the internal surface of sleeve 16, spacer 18, and bore 26 at port 14. For this purpose, bolt 60 is so designed that it can be unscrewed sutficiently to clear stop member 66 of base 24 so that the slide plate can be easily removed by grasping the bolt and sliding plate 44 off the right end of base 24 of FIGS. 2 and 3. This can usually be accomplished without using wrenches or other tools since bolts 60 can normally be backed off by hand. Handle knob 64 may be hexagonal or of any other suitable shape to permit grasping surfaces for ease in unscrewing the bolt, however, in case sticking should occur.

Slide plate 44 is slidable between the limit positions defined by stops 60 and 70 so that viewing lens 50 is alternatively in registration with bore 26 of support base 24 when plate 44 is slid to the extreme right position of FIG. 2 and in spaced relationship away from the boiler side wall when slid to the extreme left as shown in FIG. 2. When viewing lens 50 is out of registration with spacer mount 18 and port 14, to the extreme left as shown in FIG. 2, it can be easily cleaned on both sides without danger of burn injury. The cleaning can be accomplished in situ since cylindrical spacer 18 maintains the viewing assembly a distance of at least 2 inches from the boiler side plate 10. The space can be increased to any distance desired by varying the length of spacer 10 or by the use of an adapter section or collar (not shown). This space enables simple manual cleaning of the viewing window when it is in the extreme left limit position as shown in FIG. 2. Additionally, the entire assembly may be adjusted in distance from side wall plates 10 by rotation of the assembly in a counterclockwise direction which threadably withdraws spacer member 18 from sleeve 16.

Spring loaded screws 32 allow track members 34 to be resiliently moved away from support base 24 to provide greater clearance for slide plate 44 when carbon deposits build up on the blank portion 55 of the slide plate 44. As explained previously, the spring pressure should be maintained slightly higher than the maximum internal boiler pressure. The compression of springs 42 is desirably maintained at a level sufiiciently high to prevent boiler pressure loss by movement of plate 44 away from base 24. Track members 34 evenly maintain this constant pressure along the entire length of slide plate 44 preventing loss of pressure through observation ports 14 of the boiler. In this manner, the boiler observation port is constantly sealed whether lens 50 is in registration with the port or out of registration therewith. Facing of the slide plate has been found to be unnecessary since soot buildup on the plate undersurface quickly seals any leaks.

Referring now to FIG. 4 which is a cross section through the slide Plate of FIG. 3 substantially along line 44, it can be seen that viewing lens 50 is flr-mly held in position between annular ring clamp 52 and the base of inset 48 on slide plate 44 to allow visual inspection of the furnace interior when in registration with port 14. This manner of mounting lens 50 prevents scratching of the lens by means of rubbing against base support 24 during sliding of plate 44 and also reduces overheating of the lens since it is spaced substantially the distance of the length of spacer member 18, the thickness of base support 24 and the thickness of slide plate 44 from the boiler interior. The clamping ring 52 and all other members of the assembly are most conveniently machined from cold-rolled, low carbon steel, although any similar suitably strong, heat-resistant, and machinable metals may be used.

With continued reference to FIG. 4, removal of the lens for replacement due to breakage, excessive wear or other reasons may be accomplished simply by removing screws 54 and metal ring clamp 52 and pushing the window away from slide 44. The assembly of this invention facilitates lens removal without opening of the observation port since the operators hand or other instrument can easily be inserted behind slide plate 44 to push the window out of inset 48 once clamping ring 52 has been removed. The arrangement of the viewing assembly of this invention eliminates the need for using a sharp instrument to pry the viewing lens from its mount which often results in damaging of the mount.

Many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof and therefore only such limitations should be imposed as are indicated in the appended claims.

I claim:

.1. A viewing door assembly for boilers and the like having an observation port on one of its walls comprising:

a rigid slide member having a lens portion and a blank portion;

means for mounting said slide n ember in substantially fluid tight relation with said observation port and in spaced relation with said one wall so that said lens portion and said blank portion are alternatively slidable into registration with said observation port, said spacing being suflicient to permit in situ cleaning of said lens when said blank portion is in registration with said port;

means for compensating for expansion and contraction of said assembly to maintain said slide member in substantially fluid tight relation with said port while permitting manual sliding of said slide member; and

stop means for limiting the sliding movement of said slide member.

2. A viewing door assembly as defined in claim ll wherein said mounting means comprises a hollow cylindrical spacer member fixedly attached to a substantially planar slide support base, said support base having an annular through bore mounted in registration with the bore of said spacer member.

3. A viewing door assembly as defined in claim 2 wherein said compensating means comprises a pair of guide rails resiliently mounted on said support base for guiding sliding movement of said slide member.

4. A viewing door assembly as defined in claim 3 wherein said guide rails are resiliently mounted by means of spring loaded screws.

5. A viewing door assembly for viewing boiler and the like interiors through an observation port comprising:

a cylindrical, hollow spacer member mounted in registration with said observation port;

a slide support plate rigidly mounted on said spacer member;

a pair of slide guide rails resiliently mounted along opposite edges of said support plate and having flanges extending inwardly therefrom; and

a slide plate having a blank portion and a lens portion, said plate being mounted in sealed relation with said observation port under said flanges for sliding movement between blanking and viewing positions so that when said slide plate is in said blanking position said viewing portion is spaced from the boiler and can be cleaned in situ.

6. A viewing door assembly as defined in claim 5 wherein said guide rails are biased toward said support plate by spring loaded screws which exert a pressure sufficiently great to prevent movement of said slide plate by the internal pressure in said observation port.

7. A viewing door assembly for observation ports of boilers and the like comprising:

means for mounting said viewing door in a spaced relationship with a wall through which said observation port extends and in viewing relation with said observation port;

platform means fixedly mounted on said mounting means and having a through passage in viewing relation with said port;

guide tracks mounted on said platform means; and

a slidably mounted rigid viewing member comprising:

means for following said tracks; and

lens means for moving into and out of registration with said port including means for permitting in situ cleaning of said lens and for maintaining said port sealed to the atmosphere when said lens means is moved out of registration with said port.

8. A viewing door assembly as defined in claim 7 wherein said rigid slidable viewing member further comprises a planar slide plate having a blank portion and a viewing portion, said lens means being mounted in said viewing portion and said portions being alternatively slidable into and out of registration with said port.

9. A sliding viewing door assembly as defined in claim 8 wherein said slidable viewing member is constructed so that when said blank portion is in registration with said port said viewing portion extends beyond said port in spaced relation from said wall so that said viewing member is easily cleanable without removal from said assembly.

10. A sliding viewing door assembly as defined in claim 7 further including means for biasing said guide tracks toward said platform means to maintain said slidable viewing member in substantially fluid tight relationship with the through passage of said platform means.

11. A sliding viewing door as defined in claim Ilt) wherein said biasing means are manually adjustable.

12. A sliding viewing door as defined in claim 7 wherein said slidable viewing member includes a stop member at one end thereof and an adjustably mounted combination slide actuator and stop member at the opposite end thereof.

References Cited UNITED STATES PATENTS 1,417,976 5/1922 Curry et al 126-200 2,288,143 6/ 1942 Sheppard 126200 XR 2,733,707 2/1956 Skibiski 126200 2,926,658 3/1960 Ligon l26--200 3,234,899 2/1966 Mueller 126-200 KENNETH W. SPRAGUE, Primary Examiner. 

